Me: I should probably go to sleep it’s like 3 am. Brain: WHERE are all the ALIENS?!

Arthur C. Clarke - 'Two possibilities exist: either we are alone in the Universe or we are not. Both are equally terrifying.'

When he said, "I think we are alone" that totally caught me off guard. Did not expect that at all.

I'm unconvinced we're alone due to our limited knowledge at this time, but I love his inspiring closing message. We imagine all these advanced alien civilizations one day reaching us, but it hasn't happened... So we can BE that advanced civilization that reaches out instead. Absolutely exciting!

When aliens fly by our planet they roll up their windows and avoid eye contact.

i am 20 and i just wish that atleast before i die,i get to see a real proof of intelligent aliens.i just dont wanna die knowing that we dont share this incredible universe with any other intelligent being.

The problem with the argument against other intelligent life is that it is based on the limited perception of Humans, which in turn is based on our limited existence on Earth and the theories/formula's proposed to explain what we have encountered since. No doubt, other life may exist on a plane that we have not even come close to conceiving of yet. We think we're 'intelligent' as a species by our own standards, but may be considered inanimate by a species who has existed for millennia longer. A cave man could never have conceived of Virtual Reality, KZfaq, cell phones or the like and if presented with it may even think it was another way of existing altogether - which maybe it is.

Ive always thought we're alone for many of these same reasons. I never found it depressing either, I found myself feeling incredibly lucky.

Humans have been broadcasting radio waves for about 100 years, so our furthest signal is about 100 light years away. If the universe (~93 billion light years across) were the size of the pacific ocean (~11,000 km across), then our furthest radio waves have reached about 12 millimeters. But we can't even observe our nearest star in any detail and that's only 4 light years away (~half a millimeter). On this scale the Milky Way galaxy is about 12 meters across and Pluto would be about 75,000th of a millimeter away. So it'll be about another 90k years before our signal reaches the edge of just our own galaxy, and then double that to receive a response. A civilization could have started much sooner than ours and have been broadcasting a lot sooner as well, but depending on how far away it is, it could take 1000's of years to respond, so we might as well be alone. A conversation with Mars could take up to 20 minutes for a response, so I couldn't imagine how excruciating it would be to try to have a conversation with someone 10k light years away lol.

If aliens are anything like us then lets hope there aren't any.

Scientists: where are all the aliens?? Aliens: dude we’re literally buzzing your navy ships

THIS GUY IS AN ALIEN TRYING TO DEFLECT HIS EXISTENCE IN OUR MINDS! 😂

Tyson said it best. Humans take a glass of water from the ocean and say "There are no whales in the ocean!"

Nobody: Me: looks up aliens on KZfaq @ 4am

I love this idea...that we are possibly the first civilization that will in time ( a long time) visit other planets and lend a hand overcoming the barriers those younger life forms face...we have a lot of growing up to do here in the meantime...

I never hear scientists explain how time might be a crucial factor. Considering we've only been around for a short time, isn't it possible other intelligent life could have existed during before multi-cell species on Earth existed? Or maybe after we're gone? I'm not sure if these theories and their equations take time into account.

The sad paradox is that the size of the universe means there is almost certainly life out there, and we will almost certainly never find them.

No matter what they say, Earth is our only home right now. So, protect it. Nobody wants to live in a dirty home.

Interesting scope. Very well laid out. Thank you for your time. 🖤

Extremely interesting and eye opening video, but I fail to believe there's no other intelligent life in this vast universe of ours with its trillions of galaxies. We probably haven't heard from them yet because they're thousands if not millions of light years away. Intelligent life can come about out there in different ways to how it has evolved on Earth- especially if its non- carbon based.

Where are all the aliens? Alien places, probably doing alien things.

Do Aliens really need our same properties of life? What about intelligent life forms that have developed qualities that allow them to live under extreme circumstances? Maybe an octopus that’s adapted a way to leave its environment and can still thrive in space without any repercussions all while colonizing different planets and yet adapting even more durable features?

It's ridiculous to think that we're alone.

I don’t think that in the entire universe the conditions required for life is exactly the same as here. I think there will be all sorts of outcomes on different planets that we would never understand.

"Sometimes I think we're alone in the universe, and sometimes I think we're not. In either case the idea is quite STAGGERING" Arthur Clarke.

Alien speak to another alien "do we need to invade", "nah just wait, human kill each other"

I have watched this video easily twenty times over the last few years. I love the sense of wonder.

there are so many variables to the development of life its almost impossible to say whether we're alone or not. Such an interesting field of research, especially in how life began on earth

All of the aliens are in a party where humans aren't invited because we're not cool enough to be.

"Two possibilities exist: either we are alone in the Universe or we are not. Both are equally terrifying. -Arthur C. Clarke. A lot of people think humanity is a form of virus. What if aliens have isolated us to this system of the galaxy? Maybe we are just too far away/isolated to see or interact with other species.

I was wondering where he was going with the speech but I knew he was leading us to something. Awesome message. Thanks Stephen!

This is my 1st simply flat TED talk I ever listened....but bring 's about 1000 questions in my mind .... quiet interesting 👍🏻

To me his accent and voice are soothing and satisfying

It's more logical to belive that they are so advanced or so different from life on Earth that they are pratically undetectable with current technology

Earth might be one of a kind gift from the universe. There are no word in our vocabulary to define how precious it is.

To me the key question is, if you have all the conditions for life; chemicals, conditions, etc; how likely is it for lifeforms to spontaneously generate. If it is easy for life to generate then there is very likely other life that originated independently on other planets. If it is difficult then maybe either life has only originated once and that is here on earth, or the seeds of life were carried here from somewhere else and have spread around the galaxy or the universe.

Imagine if we are the only life forms in the Universe and life on Earth is ended by war, disease, etc. In that moment it means all life in the Universe would be gone, no life to live, just rocks and dust drifting throughout.

Aliens: "oh, there is life on that blue planet" ... "oh, it's underdeveloped and stuck in evolution phase 2x7b" ... "that's sooo boooring!" ... "let's drive by... before they notice us" :)

I believe Stephen Webb’s idea and the Rare Earth Hypothesis at the Galaxy level is probably closer to being true then the Galaxy is teaming with intelligent multi cellular life

Very well spoken. Kudos to you sir!

I’ve said it before I’ll say it again if we are the only intelligent beings in all the galaxy’s what a waste of space.

Imagine aliens come and watches all the movies we made.. their first target would be LA

To say that humanity is the only life in universe is a trully extraordinary statement really. Even a suspiciously religious one. Having in mind all that vastness, and potential infinity of stars / planets, the number 1 just seems somewhat like a magical wishful statement. If there is one there has to be others. We are not so special for sure. if we occured in this environment, it is not rational to think it's only once - why even think so? We are the proof of life in universe. It occurs.

What a great talk ....I could listen to the speaker for hours. There is a part of me that really wants to believe that there is "intelligent" life on another planet, but every point made in this talk makes that unlikely. Plus, I'm not sure we are even "intelligent" life, given the current state of things on this fragile Earth.

2 Aliens in a ship observing Earth. 1st Alien "I see Humankind have developed nuclear weapon technology." 2nd Alien "But are they dangerous?" 1st Alien "I don't think so. They have them all pointed at each other."

I experience alien life forms every single time I venture into a Walmart.

Such an amazing talk.

No one in the talk knows enough to declare we are alone

"In any KZfaq discussion of aliens, two possibilities exist: either someone will cite Arthur C Clarke's "alone in the universe" quote within the first 20 comments, or within the first 50 comments... both are equally annoying" -me

Aliens: "ah universe is so peaceful" Humans: *entered the chat Aliens: "Aight im out"

I'd have to agree with you sir.. There's far too many unlikely events that had to transpire for us to be here and to also evolve intelligence..

At 11:44 he states: “I think we’re alone.” And in our solar system we are. We have to be an experiment of an advance civilization to see how we turn out. The “creators” will either advance us or let us kill ourselves as not worthy of advancing. Let’s prove them wrong!

Even if there was a spacefaring civilization the way I like to imagine or describe the problem of contact with an alien species is to imagine every planet in the galaxy being a grain of sand on a beach, and one of those grains of sand is blue and that's Earth, and then you take a few wooden planks each one represents a spacefaring civilization, you then drop those wooden planks on to the beach at random, now each wooden plank is going to be touching dozens if not hundreds of grains of sand, which represents touching hundreds of planets with their space travel, but the chances of those planks touching that one blue Speck of sand is still incredibly small.

I like how he says a trillion may be a small number. This helps me understand that aliens, despite the trillions of planets, or galaxies, or universes, are still too few and far between. With more time, I think the ones evolved in the "summer months" will be contacting us before we contact them.

So he and his friend BOTH saw same ufo together? And he says that mind played a trick for BOTH of them at the same time?

What is even more startling is that life on this planet has been nearly wiped out several times.

I see flying saucers all the time, then occasionally, she'll throw the cup as well at me. 😂 😂 😂

amazing, thank you!

Fantastic talk.

WOW!!!! Beautiful exposition presented with style and grace,

I reject the whole "goldilocks zone" hypothesis. It's assuming all aliens have to be like us. If we ever find life on other planets it won't be immediately recognized as such because it's so different from anything on earth

Last summer ( 2019 ) I believe it was around July. I had just gotten of work at 11pm and my job at that time was about 300 yards from my home. I had to cross two streets and pass through a grass reservoir to get to the fence to my backyard. That night, as I was crossing the second street that leads to the reservoir, I noticed what looked like head lights ( like the lights of a Cessna airplane and then as I got closer, I noticed it was very low, like 100 ft from the ground and then I noticed it was stationary and I wasn’t moving and it was hovering above a neighbors house, two houses to the left of my home. As I got to within 50 yards of this object, I saw that it was all black and was shaped like a triangle, but it subtly curved and was making a low humming sound. My reaction was to call my wife and tell her to come out to the backyard to witness what I was seeing. She was asleep. After I tried to call her I watched this object turn from facing south to facing East ( it turned in its stationary position ) at that point my adrenaline rushed and I felt panicked. The humming sound started increasing and this object slowly headed East and gradually increased its speed until it was out of my sight. The thing I found odd was that any video I’ve ever seen of a UFO , they had lights around the edges or underneath, but this craft had headlights. This was in Tulsa Oklahoma. Immediately tried to research any military bases that might’ve been close and the only base I found was Tinker Air Force base in the OKC area, but this object headed East. I couldn’t find any images of this object / craft reported anywhere else and I didn’t want to call the police and sound like a loony. I didn’t have the presence of mind to record a video, but I was very shaken up from witnessing this. I’ve seen a lot of crazy things in my 40 years on earth, but this took the cake. I haven’t seen this object since or anything like it since. On a funny note, I didn’t see any bodies being lifted or transported out of their home.

Of all the debates and talks i have heard and watched to date.This is the one that makes sense in the real world.We are the ones that will civilise space.If we dont destroy ourselves.

"Technology itself forms the barrier to a truly advanced civilization" That's a very valid point. Another thing to consider, as he said, we've only really had advanced civilization for seconds on the day of the universe. Perhaps they only check in every 15 minutes.

Maybe aliens stopping to talk to us would be like us stopping to talk to an ant on the sidewalk.

It's interesting that he mentions the self-replicating probes (Von Neuman Machines) that one alien technological civilization out of millions (it only takes one to perfect this process) might construct... If it takes a 1,000, 000 years for a probe to replicate itself then in 100m years there should be more probes than there are planets in the entire universe. Earth itself should be host to thousands of such probes and yet...crickets.

I’m 18, and I hope in my lifetime we’re able to make some sort of breakthrough or contact with other worldly beings. With the advancements of technology I’m hopeful by the time I’m older we’ll have some sort of way of finding out if intelligent life is truly out there. Idk why but the idea of humans being the only advanced forms of intelligent life in a universe full of trillions of planets is unnerving. Even if we discovered intelligent life once existing out there, would be extremely fascinating.

I encourage you to read C.S. Lewis’ Space Trilogy. It will make you think about one possibility for life on other planets.

Beautiful message in the end. With the amount of fortunate events that have occurred in order for intelligent life to exist, it is a real shame that life is not intelligent enough to take care of their special oasis in the middle of an almost infinitely and apparently empty desert.

What if aliens are watching us like vlogs 24/7. 😳

I concur with the speaker "We are alone" and are comforted by this, because the opposite would be if we ever did detect the existence of other intelligent life forms our species would destroy its self over the the fact we were not alone.

im so fuggen high

On nights (like this) when I lie awake in bed unable to sleep, I often come back to this talk. Stephen's perspective is not new, but his own belief in it - that we're the lucky one and that we have so much to be grateful for - shines through. A wise man once said "a true thing, poorly expressed, is a lie". I don't know if the perspective here is the truth, but I feel there's probably no purer expression of it. Thank you. We've got a lot of work to do.

When Oumuamua past by it either drop some off or it started something since early 2017 until the December. Its closets fly by was Oct 16 2017. Lots of sightings around that time.

Everybody is talking about "Where are aliens?" But nobody is talking about "How are aliens?"

It's not just where, it's also when.

We are able to observe so little of the universe and yet we are astonished by it's size.

Its simple. To travel from star to star, a creature needs to travel very fast, perhaps at light speed. If we could not reach that speed, then we are not intelligent enough to be recognised. Also if they travel, they travel in hyper-space. They are there and we see them daily as a ray of light. My suggestion, only 2 things 1. Try to achieve the speed of light, even an unmanned vehicle, then they say, hey there's one out there. 2. We develop an ultra high speed camera that when we slowed it down the travelling image could be seen, perhaps we could see a space craft

Been reading his book If the Universe is Teeming with Life, Where is everybody?. A great book with seemingly logical answers as to why we’ve not heard from or met Aliens. Worth reading

According to that clock of 24 hours, we've only been looking for 0.000001 seconds... Still, its plausible its just us and yet we still can't work out how to put on a quilt cover alone without getting angry.

"Opens door to house in middle of the artic scanning the horizon* "WHERE ARE ALL THE HUMANS?! Guess there aren't any!"

I’ve always wondered, what if we’re first? Everyone talks about “oh the universe is so large there HAS to be others” well maybe, but someone has to be first and what if that’s us?

Happy that Satya Nadella is an active speaker on Ted.

Absolutely amazing. Chills running down my spine at the end of this talk. Wow!

Do humans try to communicate with ants? I mean, we've observed them. Learned about them. But they pose no threat. Insignificant.

Mr. Webb said something that is very interesting; he said "what we expect". maybe that is the problem, from where , or who gave us the idea that what we expect is important to other forms of life.

It is important to know that saying, believing "we are alone" and "we are not alone" does not even matter. Each is right, each is wrong. Ultimately, it really does not matter. What matters is you just keep looking, honestly searching...most of all...having some form of hope....Hope is what will keep us humans moving through time, for days to come...

The first question to be asked, according to my twisted way of reasoning, is, "What is your definition of the term 'Alien'"? The second is: "If an alien were standing behind you in a supermarket check-out queue, are you so sure that you would recognize him/her/it as such"? The only way you would (or perhaps wouldn't) freakout is if the alien looked exactly like your preconceived idea of what an alien should/would look like. When I was a young, ten years old boy in 1950's Ohio, the subject of aliens came up while on an overnight, cat-fishing trip with my older brother and our grandfather. We were all gazing at the stars and talking about aliens (aliens were a big thing in low budget, black and white, Sci-Fi movies then) while waiting for the fish to bite. During our conversation, I happened to say, quite honestly, "I wish that I could meet someone from Outer Space". With that, my grandfather stuck out his hand and said, "Hello there, Earthling, nice to meet you". "Aw, common, grandpa, you're not from Outer Space, you came from right here on Earth", I complained. He said, "Pick out a star up there" and he waved his arm in a wide arch through the star-filled night sky. "Now, imagine," he said "if another group was on one of the planets orbiting around that star. and that they were looking up into their night sky looking back at us... follow?" "Then, where would we be?" "In outer space", I cried. That means that we are aliens... we are from outer space!" At that moment, my entire perspective of relationships of all sorts changed. I realized that the answer to any question depended, entirely, on own's own perspective. A lioness killing a lamb might seem to us like a bad thing; however, for the two hungry lion cubs waiting at home for the mother to bring dinner, it's very much a good thing. So, "Where are all the Aliens? You're looking at them." Thank you for reminding me of that magical moment so long ago.

"We have searched thousands of these floor tiles for several types of pheromone trails. If there were intelligent life out there we would have found it by now." - Ants :P

He said exactly how I feel about alien life. I'm so glad scientists agree with me. Just because we are here and there are many other planets, doesn't mean there HAS to be other life anywhere. That's the absolute truth. All we know is that life is possible, and only carbon based life at the moment.

If we are alone in this huge cosmos thats damn sad and makes me very melancolic.

We're in no position right now to say that we are alone. We're just beginning to understand how the universe works. We've barely scratched the surface. I disagree completely with him. Though I believe intelligent life is probably very rare, maybe only a few examples per galaxy. But it's there! It's also the type of thing that could be another 100 years before we conclusively know..

Anybody who asks "where are the aliens" really doesn't appreciate how big and old the universe is. We started listening to the radio noise in the sky within the last hundred years. But we have *never* listened to the whole sky at once, we simply can't. We pick and choose little bits of sky and hope that maybe we will catch a snippet of something sent at just the right time so as to reach us when we happen to be listening. It's profoundly ignorant to conclude based on a few decades of observation that we are alone in the universe... the universe doesn't operate on scales so small. Consider if our galaxy had one million civilizations in it, existing at different times in the past, present, and future. For some length of time these civilizations use radio communications before they die out or move to some other form of communication. Assume on average that each of these civilizations transmits for 500 years (that's WAY longer than we've been transmitting, and there's no guarantee that we'll be here in 500 years). If you take these assumptions and consider the size of the galaxy, it immediately becomes apparent that: 1. many of these civs communications started and stopped before we were listening 2. many of these civs communications started, but are so far away (galaxy is 100,000 LY wide folks), they won't reach us for thousands of years 3. for those few civs who's communications could have reached us in the few decades we have been listening, we have to have been listening at the exact right time, in the exact right direction As a thought experiment, I once did this computation. Over a stretch of 9 billion years, assume 1 million civilizations arise in our galaxy (including ours at the 4.5 billion year mark). Assume they transmit radio for a span of 100-1000 years each. Question: if we could listen NON STOP in ALL DIRECTIONS for 1,000 years, what is the chance we would hear nothing at all? Answer: 87%. There would be an 11% chance of hearing one civilization, and a minute chance of hearing two. The universe is really, really big. If you are asking "why don't we hear anything" you don't get how big it is. In my opinion, it is likely that the universe is teeming with life, and there are undoubtedly multiple intelligent civilizations located in our own galaxy. We will almost certainly NEVER ENCOUNTER ANY OF THEM. Why haven't we heard anything? LOL. Get back to me after 10,000 years of constant observation in all directions. If you haven't done that yet, you haven't even started listening.

How saddened I felt when he said, "We are alone", the thought is scary and amazing. So much out there.

i like him. he's good. calm and smooth.

"If the universe was the size of the pacific ocean, our search for aliens covers the volume of a cup of water." - Me, just now

someone beat me to it, but indulge me; absence of proof doesn't mean proof of absence..

Instead of focusing on other planets, our focus must be on earth itself। We have many information yet to be explored।

This guy is a pleasant-sounding, narrow-minded speaker. If a person was born in the woods, 500 miles away from his nearest neighbor, and never left his home (except once, to go to the shed), he could easily think he's alone on Earth. Especially if he saw a plane fly by and his parents told him he must be crazy.

We are just atoms of a bigger ‘host’